INTRODUCTION TO CRYPTOGAMIC BOTANY. 477 



TricJiostomei ; indeed, he lias placed Ceratodon both in Tri- 

 chostomei and Weissiei. Brucli and Schimper separate two 

 distinct tribes from Weissiei, under the names of Campylo- 

 stelei and Seligerei, the. former of which includes the British 

 genera Cam^jylosteliwiii and Brachyodus, and the latter Seli- 

 geria and Anodus. Bliiidia is also included in the latter^ 

 but Wilson places this with Dicranei. Campylostelium has 

 a drooping geniculate peduncle, but Brachyodus, included with 

 it, has an erect sporangium ; the Seligerei are very minute, 

 and their sporangia pyriform. The characters, however, at 

 present seem very uncertain, and I prefer, therefore, following 

 the arrangement of Montagne. 



3. Dicranei, Mont. (Dickanace^, Br. & Sc). 



Sporangium even or striated ; peristome single, consisting 

 of sixteen teeth, split half-way down. Calyptra cuculliform, 

 naked at the base or fringed. 



527. This tribe contains a large mass of species, which are 

 easily known by the teeth of the peristome being divided half- 

 way down.* Some of the species are amongst the most com- 

 mon of mosses. 8tylostegium and Blindia, which form the 

 bases of two distinct tribes, appear amongst Dicranei in 

 Wilson's arrangement, instead of amongst Weissiei, as in that 

 of Montagne. The former has no peristome, and in the latter 

 the teeth are not uniformly cloven, but sometimes perforated, 

 Garayylo'pus is separated under a distinct tribe, because of 

 its fringed calyptra ; but the multiplication of tribes, as of all 

 divisions, beyond absolute necessity, is a great evil. It is, how- 

 ever, easUy distinguished by this character, as also by the 

 arcuate peduncle, and the lamelliferous ribs of the leaves (Fig. 

 99, g). Sandstone rocks, turbaries, shady banks, the trunks 

 of trees, &c., are the favourite localities of these mosses, whose 

 leaves are with few exceptions drawn out into long subulate 

 points. Many of the species are minute ; but others, again, are 

 amongst the finer mosses. Leucohryum is remarkable for the 

 pallid leaves, which have perforated walls (Fig. 99, h) like those 



* This cliaracter is not, however, absolute or invariable. In D. Tas- 

 manicum, cerviculatum, and others, they are frequently trifid. 



